The Dials incorporate sunray and guilloche finishes, and therefore are always shielded by scratch-resistant sapphire crystals. Hooked up towards the scenarios are buttery-clean Barenia leather straps, normally in the colour of the selecting. ZENITH carries on Discovering Innovative watchmaking methods while developing the El Primero into new issues In 1957, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/